vnode.c

Solaris操作系统下的过滤驱动程序, C源码程序.

  /* CNP_VARS; */
  cn_t *thisfcnp, *lowerfcnp, *thistcnp, *lowertcnp;

  if (thistvp != NULL)		/* comes in as null to this function */
    lowertvp = WRAPFS_VP_TO_LOWERVP(thistvp);

  fist_dprint(2, "WRAPFS_RENAME: thisfdvp=0x%x thisfvp=0x%x thistdvp=0x%x thistvp=0x%x\n",
	      (int) thisfdvp, (int) thisfvp,
	      (int) thistdvp, (int) thistvp);
  fist_dprint(2, "WRAPFS_RENAME: lowerfdvp=0x%x lowerfvp=0x%x lowertdvp=0x%x lowertvp=0x%x\n",
	      (int) lowerfdvp, (int) lowerfvp,
	      (int) lowertdvp, (int) lowertvp);

  /* CNP_BEFORE(thisvp); */
  thisfcnp = ap->a_fcnp;	/* save original */
  lowerfcnp = wrapfs_new_cnp((thisfdvp), thisfcnp);
  ap->a_fcnp = lowerfcnp;	/* prepare for bypass */
  thistcnp = ap->a_tcnp;	/* save original */
  lowertcnp = wrapfs_new_cnp((thistdvp), thistcnp);
  ap->a_tcnp = lowertcnp;	/* prepare for bypass */

  error = wrapfs_bypass((struct vop_generic_args *) ap);

  /* CNP_AFTER(thisvp); */
  if ((thisfcnp->cn_flags & PARAMASK) != (lowerfcnp->cn_flags & PARAMASK))
    panic("%s: FLAGS CHANGED fthis:0x%x flower:0x%x",
	  __FUNCTION__, (int)thisfcnp->cn_flags, (int)lowerfcnp->cn_flags);
  if ((thistcnp->cn_flags & PARAMASK) != (lowertcnp->cn_flags & PARAMASK))
    panic("%s: FLAGS CHANGED tthis:0x%x tlower:0x%x",
	  __FUNCTION__, (int)thistcnp->cn_flags, (int)lowertcnp->cn_flags);
  wrapfs_update_cnp((thisfdvp), &lowerfcnp, thisfcnp, error);
  ap->a_fcnp = thisfcnp;	/* update for caller */
  wrapfs_update_cnp((thistdvp), &lowertcnp, thistcnp, error);
  ap->a_tcnp = thistcnp;	/* update for caller */

  print_location();
  return (error);
}

static int
wrapfs_link(ap)
     struct vop_link_args /* {
			     struct vnode *a_tdvp;
			     struct vnode *a_vp;
			     struct componentname *a_cnp;
			     } */ *ap;
{
  int error;
  vnode_t *thistdvp = ap->a_tdvp;
  vnode_t *thisvp = ap->a_vp;
  vnode_t *lowertdvp = NULL;
  vnode_t *lowervp = NULL;
  CNP_VARS;

  /* MUST make sure we only hard link into our own file system! */
  if (thisvp->v_op != wrapfs_vnodeop_p)
    return EXDEV;

  lowertdvp = WRAPFS_VP_TO_LOWERVP(thistdvp);
  lowervp = WRAPFS_VP_TO_LOWERVP(thisvp);
  fist_dprint(2, "WRAPFS_LINK: lowertdvp=0x%x lowervp=0x%x\n",
	      (int) lowertdvp, (int) lowervp);

  CNP_BEFORE(thistdvp);
  error = wrapfs_bypass((struct vop_generic_args *) ap);
  CNP_AFTER(thistdvp);

  print_location();
  return (error);
}

static int
wrapfs_symlink(ap)
     struct vop_symlink_args /* {
				struct vnode *a_dvp;
				struct vnode **a_vpp;
				struct componentname *a_cnp;
				struct vattr *a_vap;
				char *a_target;
				} */ *ap;
{
  int error;
  vnode_t *thisdvp = ap->a_dvp;
  vnode_t *lowerdvp = WRAPFS_VP_TO_LOWERVP(thisdvp);
  char *lower_target, *this_target;
  int lower_target_len = 0;
  CNP_VARS;

  fist_dprint(2, "WRAPFS_SYMLINK: lowerdvp=0x%x target=\"%s\"\n",
	      (int) lowerdvp, ap->a_target);

  lower_target_len = wrapfs_encode_filename(ap->a_target,
					    strlen(ap->a_target),
					    &lower_target,
					    DO_DOTS,
					    thisdvp,
					    thisdvp->v_mount);
  this_target = ap->a_target;	/* save pointer */
  ap->a_target = lower_target;	/* set to encoded name */
  CNP_BEFORE(thisdvp);
  error = wrapfs_bypass((struct vop_generic_args *) ap);
  CNP_AFTER(thisdvp);
  ap->a_target = this_target;	/* restore pointer */
  kmem_free(lower_target);

  print_location();
  return (error);
}

static int
wrapfs_readlink(ap)
     struct vop_readlink_args /* {
				 struct vnode *a_vp;
				 struct uio *a_uio;
				 struct ucred *a_cred;
				 } */ *ap;
{
  int error;
  vnode_t *thisvp = ap->a_vp;
  vnode_t *lowervp = WRAPFS_VP_TO_LOWERVP(thisvp);
  uio_t *uiop = ap->a_uio;
  cred_t *cr = ap->a_cred;
  iovec_t temp_iovec;
  uio_t temp_uio;
  caddr_t temp_addr2free;
  int bytes_read;
  int temp_length, target_real_length;
  char *temp_name;

  fist_dprint(2, "WRAPFS_READLINK: lowervp=0x%x\n",
	      (int) lowervp);

  temp_iovec.iov_len = PAGE_SIZE;
  temp_iovec.iov_base = temp_addr2free = kmem_zalloc(PAGE_SIZE);
  if (!temp_iovec.iov_base) {
    printf("no more memory in readlink\n");
    error = ENOMEM;
    goto out;
  }
  temp_uio.uio_iov = &temp_iovec;
  temp_uio.uio_iovcnt = 1;
  temp_uio.uio_offset = 0;
  temp_uio.uio_segflg = UIO_SYSSPACE;
  temp_uio.uio_rw = uiop->uio_rw;
  temp_uio.uio_procp = uiop->uio_procp;
  temp_uio.uio_resid = uiop->uio_resid;

  error = VOP_READLINK(lowervp, &temp_uio, cr);
  if (error)
    goto out_free;

  bytes_read = PAGE_SIZE - temp_iovec.iov_len;

  temp_length = wrapfs_decode_filename(temp_iovec.iov_base - bytes_read,
				       bytes_read,
				       &temp_name,
				       DO_DOTS,
				       thisvp,
				       thisvp->v_mount);
  if (temp_length < 0) {
    /* a checksum error had occured: skip entry */
    panic("symlink value encoded with different key than link itself");
  }
  /* must find real string length, which is guaranteed null terminated here */
  target_real_length = strlen(temp_name) + 1;
  fist_dprint(4, "wrapfs_readlink DECODE len=%d, real_len=%d, bytes_read=%d, name=\"%s\"",
	      temp_length, target_real_length, bytes_read, temp_name);

  fist_uiomove(temp_name, target_real_length, UIO_READ, uiop);
  /* already OK: uiop->uio_resid and uiop->uio_loffset */

out_free:
  kmem_free(temp_name);
  kmem_free(temp_addr2free);

out:
  print_location();
  return (error);
}

#if 0
static int
wrapfs_cachedlookup(ap)
     struct vop_cachedlookup_args /* {
				     struct vnode *a_dvp;
				     struct vnode **a_vpp;
				     struct componentname *a_cnp;
				     } */ *ap;
{
  int error;
  vnode_t *thisdvp = ap->a_dvp;
  vnode_t *lowerdvp = WRAPFS_VP_TO_LOWERVP(thisdvp);
  CNP_VARS;

  fist_dprint(2, "WRAPFS_CACHEDLOOKUP: lowerdvp=0x%x\n",
	      (int) lowerdvp);
  panic("WRAPFS_CACHEDLOOKUP: lowerdvp=0x%x\n", (int) lowerdvp);

  CNP_BEFORE(thisdvp);
  error = wrapfs_bypass((struct vop_generic_args *) ap);
  CNP_AFTER(thisdvp);

  print_location();
  return (error);
}
#endif

static int
wrapfs_whiteout(ap)
     struct vop_whiteout_args /* {
				 struct vnode *a_dvp;
				 struct componentname *a_cnp;
				 int a_flags;
				 } */ *ap;
{
  int error;
  vnode_t *thisdvp = ap->a_dvp;
  vnode_t *lowerdvp = WRAPFS_VP_TO_LOWERVP(thisdvp);
  CNP_VARS;

  fist_dprint(2, "WRAPFS_WHITEOUT: lowerdvp=0x%x\n",
	      (int) lowerdvp);

  CNP_BEFORE(thisdvp);
  error = wrapfs_bypass((struct vop_generic_args *) ap);
  CNP_AFTER(thisdvp);

  print_location();
  return (error);
}

static int
wrapfs_mknod(ap)
     struct vop_mknod_args /* {
			      struct vnode *a_dvp;
			      struct vnode **a_vpp;
			      struct componentname *a_cnp;
			      struct vattr *a_vap;
			      } */ *ap;
{
  int error;
  vnode_t *thisdvp = ap->a_dvp;
  vnode_t *lowerdvp = WRAPFS_VP_TO_LOWERVP(thisdvp);
  CNP_VARS;

  fist_dprint(2, "WRAPFS_MKNOD: lowerdvp=0x%x\n",
	      (int) lowerdvp);

  CNP_BEFORE(thisdvp);
  error = wrapfs_bypass((struct vop_generic_args *) ap);
  CNP_AFTER(thisdvp);

  print_location();
  return (error);
}


static int
wrapfs_readdir(ap)
     struct vop_readdir_args /* {
				struct vnode *a_vp;
				struct uio *a_uio;
				struct ucred *a_cred;
				int *a_eofflag;
				int *a_ncookies;
				u_long **a_cookies;
				} */ *ap;
{
  int error = EPERM;
  vnode_t *thisvp = ap->a_vp;
  vnode_t *lowervp = WRAPFS_VP_TO_LOWERVP(thisvp);
  cred_t *cr = ap->a_cred;
  uio_t *uiop = ap->a_uio;
  uio_t temp_uio;
  iovec_t temp_iovec;
  int aux, bytes_read, length, temp_length, tmp, old_reclen;
  char *temp_name;

  fist_dprint(2, "WRAPFS_READDIR: lowervp=0x%x ncookies=0x%x\n",
	      (int) lowervp, (int) ap->a_ncookies);

  if (ap->a_ncookies)
    panic("WRAPFS_READDIR0: *ncookies=%d (fix the code)\n", *ap->a_ncookies);

  if (uiop->uio_iovcnt != 1)
    panic("WRAPFS_READDIR: iovecnt not 1 (=%d)", uiop->uio_iovcnt);

  temp_iovec.iov_len = uiop->uio_resid;
  temp_iovec.iov_base = kmem_zalloc(uiop->uio_resid);

  temp_uio.uio_iov = &temp_iovec;
  temp_uio.uio_iovcnt = 1;
  temp_uio.uio_offset = uiop->uio_offset;
  temp_uio.uio_segflg = UIO_SYSSPACE;
  temp_uio.uio_rw = uiop->uio_rw;
  temp_uio.uio_procp = uiop->uio_procp;
  temp_uio.uio_resid = uiop->uio_resid;

  /* pass operation to hidden filesystem, and return status */
  error = VOP_READDIR(lowervp, &temp_uio, cr,
		      ap->a_eofflag, ap->a_ncookies, ap->a_cookies);

  bytes_read = uiop->uio_resid - temp_uio.uio_resid;
  temp_iovec.iov_base -= bytes_read;
  temp_iovec.iov_len += bytes_read;

  if (error)
    goto clean_up;

#define crt_dirent ((struct dirent *)(temp_iovec.iov_base + aux))
  for (aux = 0; aux < bytes_read; aux += old_reclen) {
    char *name = temp_name;
    old_reclen = crt_dirent->d_reclen;
    fist_dprint(2, "\nRD: old_reclen=%d old_namlen=%d\n", old_reclen, crt_dirent->d_namlen);
    /* temp_lenth includes the terminating null */
    temp_length = wrapfs_decode_filename(crt_dirent->d_name,
					 crt_dirent->d_namlen,
					 &temp_name, /* null terminated */
					 SKIP_DOTS,
					 thisvp,
					 thisvp->v_mount);
    if (temp_length >= 0) {

      FIST_OP_READDIR_CALL;

      /*
       * We copy the dirent to userspace only if the csum matched
       */
      strcpy(crt_dirent->d_name, temp_name); /* ok, b/c of terminating null */
      length = temp_length - 256 + sizeof(struct dirent);
      fist_dprint(2, "RD: new length is %d, temp_length %d, struct dirent: %d\n",
		  length, temp_length, sizeof(struct dirent));
      if ((tmp = length & 3))
	length += 4 - tmp;
      crt_dirent->d_reclen = length;
      crt_dirent->d_namlen = temp_length - 1;
      kmem_free(temp_name);
      fist_dprint(2, "RD: adding entry \"%s\" of length %d\n",
		  crt_dirent->d_name, crt_dirent->d_reclen);
      error = fist_uiomove(temp_iovec.iov_base + aux,
			   crt_dirent->d_reclen, UIO_READ, uiop);
      if (error)
	goto clean_up;
    }
  }
  uiop->uio_offset = temp_uio.uio_offset;

clean_up:
  kmem_free(temp_iovec.iov_base);
  print_location();
  return (error);
}
#endif /* FIST_FILTER_NAME */

/*
 * Global vfs data structures
 */
vop_t **wrapfs_vnodeop_p;
static struct vnodeopv_entry_desc wrapfs_vnodeop_entries[] =
{
  {&vop_default_desc,		(vop_t *) wrapfs_bypass},
  {&vop_access_desc,		(vop_t *) wrapfs_access},
  {&vop_getattr_desc,		(vop_t *) wrapfs_getattr},
  {&vop_inactive_desc,		(vop_t *) wrapfs_inactive},
  {&vop_lock_desc,		(vop_t *) wrapfs_lock},
#ifdef FIST_FILTER_NAME
  {&vop_lookup_desc,		(vop_t *) vfs_cache_lookup}, /* FIST_FILTER_NAME */
#else /* not FIST_FILTER_NAME */
  {&vop_lookup_desc,		(vop_t *) wrapfs_lookup}, /* FIST_FILTER_NAME */
#endif /* not FIST_FILTER_NAME */
  {&vop_print_desc,		(vop_t *) wrapfs_print},
  {&vop_reclaim_desc,		(vop_t *) wrapfs_reclaim},
  {&vop_setattr_desc,		(vop_t *) wrapfs_setattr},
  {&vop_unlock_desc,		(vop_t *) wrapfs_unlock},
  /* EZK added these */
  { &vop_read_desc,		(vop_t *) wrapfs_read },
  { &vop_write_desc,		(vop_t *) wrapfs_write },
  { &vop_ioctl_desc,		(vop_t *) wrapfs_ioctl },
  { &vop_getpages_desc,		(vop_t *) wrapfs_getpages },
  { &vop_putpages_desc,		(vop_t *) wrapfs_putpages },
#ifdef HAVE_BMAP
  { &vop_bmap_desc,		(vop_t *) wrapfs_bmap },
#endif /* HAVE_BMAP */
  { &vop_mmap_desc,		(vop_t *) wrapfs_mmap },
#ifdef FIST_FILTER_NAME
  { &vop_mkdir_desc,		(vop_t *) wrapfs_mkdir },
  { &vop_rmdir_desc,		(vop_t *) wrapfs_rmdir },
  { &vop_create_desc,		(vop_t *) wrapfs_create },
  { &vop_remove_desc,		(vop_t *) wrapfs_remove },
  { &vop_rename_desc,		(vop_t *) wrapfs_rename },
  { &vop_link_desc,		(vop_t *) wrapfs_link },
  { &vop_symlink_desc,		(vop_t *) wrapfs_symlink },
  { &vop_readlink_desc,		(vop_t *) wrapfs_readlink },
  { &vop_readdir_desc,		(vop_t *) wrapfs_readdir },
  /* also these are new but need to handle DO_NAMES */
#if 0
  { &vop_cachedlookup_desc,	(vop_t *) wrapfs_cachedlookup },
#else
  { &vop_cachedlookup_desc,	(vop_t *) wrapfs_lookup },
#endif
  { &vop_whiteout_desc,		(vop_t *) wrapfs_whiteout },
  { &vop_mknod_desc,		(vop_t *) wrapfs_mknod },
#endif /* FIST_FILTER_NAME */

  {NULL, NULL}
};
static struct vnodeopv_desc wrapfs_vnodeop_opv_desc = {
  &wrapfs_vnodeop_p, wrapfs_vnodeop_entries
};

VNODEOP_SET(wrapfs_vnodeop_opv_desc);